Automatic control system for acetylene generators



Nov. 25 1941. w, L ET AL 2,263,658

AUTOMATIC CONTROL SYSTEM FOR ACETYLENE GENERATORS Filed Sept. 16, 1938 3 Sheets-Sheet 1 \NVENTORS WILLIAM G. TUEL CHESTER A.SIVER ATTORNEY 0F CAMS DON SHAFT 200,0F H63.

DEVE

Nov. 25, 1941. w. G. TUEL EI'AL 2,263,658

AUTOMATIC CONTROL SYSTEM FOR AGETYLENE GENERATORS 7 Filed Sept. 16, 1958 :s Sheets-Sheet 2 9 TEE- INVENTORS WILLIAM G.TUEL CHESTER A. SIVER ATTORNEY Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE AUT OMA TIC CONTROL SYSTEM FOR ACETYLENE GENERATORS William G. Tuel and chemi- A. Siver, Indianapolis, Ind., assignors to The Prest-O-Llte Company, Inc., a corporation of New York Application September 16, 1938, Serial No. 230,226

21 Claims. (01. 48- 38) This invention relates to the art of generating acetylene gas, and particularly to semi-automatic and completely automatic control systems for starting and stopping the operating units of an acetylene generating plant in accordance with a predetermined sequential order. While the invention may be applied to all types of acetylene generating plants in which the units may be operated by various known prime-movers, pneumatically or electrically controlled, the principles of the invention will be described in connection with a so-called dry-generating" acetylene plant in which the units are driven and controlled electrically.

Usually, dry-generating plants include a calcium carbide hopper and means adapted to feed the carbide therefrom to a generating chamber to which water is fed in sufilcient quantities only to completely react with the carbide to form acetylene and dry calcium hydroxide. The gen-' erator may be provided with an agitator adapted to thoroughly mix the carbide and water to eifect maximum acetylene generation with aminimum volume of water. The generated gas may be conducted to a gas holder from which it may be withdrawn for commercial consumption. The dry calcium hydroxide may be withdrawn from the generator and collected in a lime-seal hopper from which it may be conveyed to a point of storage at a rate which will retain sufilcient lime within the hopper to provide a seal, thus prevent-- ing any loss of acetylene from, or the entrance of any air into the generator through the lime discharge means.

In order to insure the eflicient operation of, and to prevent dangerous conditions in plants of the above-outlined type, certain precautions must be observed which require starting the various operating units of the plant in accordance with a predetermined sequence. Likewise,'a sequential order of stopping certain or all of these'operating units is essential when the gas holder becomes filled, or when generation of gas is terminated. For these reasons, it has been found expedient to employ separate electrical control devices for the various generator operating units including a motor adapted to drive a conveyor for feeding the carbide'from the hopper to the generator; an electrically operated device for controlling the flow of water to the generator; a motor for operating anagitator within the generating chamber; a motor for operating an agitator in the lime-seal hopper to insurethe proper distribution of the dry lime which is fed thereto; and a motor for operating a conveyor which withdraws the lime from the lime-seal hopper and which delivers said withdrawn lime to the point of lime storage.

When the gas holder is empty, and it is desired to begin operating the system, it is necessary to initially start the lime-seal agitator motor before the dry.lime is discharged'into the limeseal hopper, otherwise the agitator will not properly distribute the lime within the lime-seal hopper and hence the lime seal will not be formed. The generator agitator must be started before feeding calcium carbide and water to the generator, otherwise an unsuitable, wet, pasty product of calcium hydroxide will result. Additionally, the feeding of calcium carbide from the carbide hopper to the generator must precede the introduction of the water to the generator, otherwise an excess of water will be initially present when the carbide reaches the generator, and an improper, wet, pasty condition of the resulting calcium hydroxide will occur. Operation of the conveyor motor drive for the lime-seal hopper must be controlled in accordance with the level of the lime within the lime-seal hopper in order to maintain the seal of said hopper at all times.

When the gasholder has been filled with gas, or when acetylene generation is to be terminated, a different sequential order of stopping the various generator operating devices must be observed from that in starting said devices. Thus, the feeding of calcium carbide from the hopper to the generator must continue for a sufficient length of time after the carbide-hopper feedvalve is closed so that the conveyor will not trap calcium carbide within its housing. The flow of water to the generator and the operation of the generator agitator must continue for a suiilcient length of time after the carbide-feed valve is shut off in order to thoroughly react the entire amount of carbide fed to the generator from within the carbide-feed-conveyor housing. In order to prevent excess accumulation of the dry lime within the lime-seal hopper, the operation of the lime-seal agitator as well as that of the lime-seal conveyor must continue until after the generator agitator has been stopped.

In such a system of interconnected electrically operated generator equipment many contingencies may arise, and provisions therefor must be employed in order to insure stopping of certain devices and continued operation of others when hazardous contingencies occur.

An object of this invention is to provide an acetylene generating plant and a control system for insuring the starting and stopping of various units of the plant in accordance with a predetermined sequential order.

Other objects of the invention include, the provision of such a plant in which a semi-automatic electrical control circuit is provided for insuring the proper sequential order of operation;

the provision of such a semi-automatic control circuit in which certain of the electrically operated units must be started before others; the provision of such a semi-automatic control circuit in which certain of the electrically operated units are cut in and cut out of an electrical circuit in accordance with the mechanical operation of said units and independently of other electrically operated units of the generating plant; the provision of such a semi-automatic control circuit in which certain of the electrically operated units are controlled by a timing unit for insuring a definite timed relation between their starting and stopping, and in which the operation of the timing unit is dependent upon the mechanical operation of certain portions of the generating plant; the provision of such a semiautomatic control circuit including a timing unit, wherein stopping of the various operating units of the plant are efiected in a sequential order different from that of starting said units; the

, provision of such a semi-automatic control circuit including a timing device for certain of the operating units of the plant, wherein said timing device is adapted to start and stop certain of said operating units during a complete cycle of its operation; and the provision of such a semiautomatic control circuit including audible means and safety features for insuring fool-proof operation of the generating plant.

Additionally, other specific objects of the invention include the provision of such a generating plant in which a fully automatic electrical control circuit is provided wherein a complete cycle of starting and stopping various operating units, in accordance with the order of operating said units as outlined inconnection with the semiautomatic control, may be efiected without the constant attention of an attendant; the provision of such a fully automatic electrical control circuit in which the starting of various operating units follows a difierent sequential order from that of stopping of said units, and wherein a seriesof timed relations are maintained between the successive starting of said units and the successive stopping of said units; and the provision of such a fully automatic control circuit including audible alarms, visible signals, and safety features for insuring fool-proof operation of the gen erating plant.

The above and other objects and novel features of the invention will become apparent from 'the detailed description in the following specification which refers to the accompanying drawings in which:

Fig; 1 is a somewhat schematic elevational view of an acetylene generating plantembodying the principles of the invention;

Fig. 2 is a wiring diagram illustrating one form of a semi-automatic electrical control circuit for the various electrically operated units of the generating plant shown in Fig. 1;

ciples of the invention are shown as applied to a dry acetylene generating plant of the type shown, described and claimed in a copending application Serial No. 241,144, filed November 18. 1938, now Patent No. 2,283,109 dated February 25, 1941, which was a divisional application of a copending application Serial No. 103,526, filed October 1, 1936, in the name of Charles Ness and Hugo V. Kojola now Patent No. 2,233,108, dated February 25, 1941. The generating plant includes upper and lower carbide hoppers Hu and H1 and a pneumatically operated carbide feedvalve V adapted to control the flow of carbide to a screw conveyor Fe which is driven by a motor Me. The carbide conveyor is adapted to discharge the carbide into a generating chamber Cg within which an agitator assembly'A is mounted for rotation by a motor Ma. The generating chamber Cg is also provided with an inlet through which water is adapted to be introduced in controlled amounts through the operation of an automatically actuated water flow controller W Fig. 3 is a wiring diagram illustrating one form r of a fully automatic electrical control circuit for the various operating units of the generating plant shown in Fig. 1; and l V Fig. 4 is a diagram representing. the cam de-. velopment of a portion of the invention.

Referring to Fig. 1 of the drawings, the prinhell 1'! Of the holder H which may be air-operated. A separating or dust-settling chamber. Cs is mounted above and in communicative registry with the generating chamber Cg. The acetylene gas generated within the chamber Cg rises within chamber Cs wherein any floating particles of dry calcium hydroxide separate or settle from the gas. The upper portionof the chamber C5 is provided with a waterseal scrubbing device S which frees the gas from any solid particles that may not have separated or settled therefrom within chamber C3. The scrubbed gas passes through a pipe system and enters a gas holder Hg from which it may be withdrawn for commercial consumption. a

The dry calcium hydroxide rises within the chamber Cg, overflows the same and discharges into an annular lime overflow located at the bottom of chamber Cs, from which the dry lime gravitates into a lime-seal hopper L. The residue-collecting means or hopper L is provided with an agitator assembly A1 adapted to be rotated by a motor Ma. The dry lime within the hopper L is adapted to be discharged into the housing of a screw conveyor F1 which latter is operated by a motor Ml for conveying the dry lime to a storage point. The rotatable agitator assembly A1 is provided with a lime level indicator which controls the operation of motor M1 to thereby automatically retain at all times, a sufficient quantity of lime within hopper L to form a lime-seal and thus prevent any loss of acetylene from, or the entrance of any air into the generating chamber Cg through the lime disposal apparatus.

The carbide hoppers H and H1 are located in substantially vertical alignment, with a gate valve l0 located at their communicating point. This arrangement of dual hoppers enables filling the upper hopper Hu while the generator is operating without admitting air t the generator through the carbide feed apparatus. R.

The pneumatically operated carbide feed-valve V is in the form of a gate valve and is connected to a piston l2 within a cylinder H. The cylinder M is provided with air lines It and II adapted to introduce air to opposite sides of the piston ii.

.A three-way operating valve II is connected to the lines I and i9, and this valve is actuated by a trip lever 13 adapted to be actuated by the movement of a lever l5 rigidly attached to a gas The arrangement is such that when the holder istull of acetylene gas and at its upper position, the three-way valve I l is operated to admit air to line It thus causing striking lever II, to admit air to line "thereby effecting the opening of valve V.

Manual control of valve V may be effected independently of the movement or position of gas bell IT, by providing a second manually operable normally closed two-way valve I8 which shunts the three-way valve II. Additionally, manually operable valves 2| and 23 may be provided in lines I8 and I8 for accomplishing this latter result.

The conveyor Fe comprises a screw 28 within a housing 22 which latter opens into the bottom of chamber C The conveyor screw 28 is adapted to be driven at variable speeds by the motor Mo through a speed reducer 24 and a gear train designated generally by the numeral 28.

The acetylene generating chamber comprises a frustro-conical container 28, open at its top and closed at its bottom by wall 38. An opening .32 is provided at the bottom of the side wall of chamber C in alignment with the discharge end of the housing 22. Anotheropening 34 is .provided in the side wall of chamber C adapted to receive the end of a water supply pipe 88. The amount of water introduced into the chamber C is only sufilcient to completely react the carbide fed into said chamber and to dissipate by its evaporation excess heat produced by the reaction, as is well known in the so-called dry-generating process. Control of the amount and rate of flow of water entering reaction chamber C is maintained by including an air-operated water flow controller W in the main water line 38, while a solenoid-operated valve 88 is provided in the line 38 for starting and stopping the flow of water into the generating chamber.

Agitation of the mixture of calcium carbide and water within chamber C3 is effected by the agitator assembly A It comprises a series of alternately arranged,- vertically spaced, oppositely rotatable paddles 48 and 42 which are driven by the motor Mg through a double-motion gear train within a gear box 44. The paddles 42 are connected to a rotatable frame 46 and are jcurnaled on a vertically disposed shaft 48; whilethe paddles 48 are fixed to and rotate with shaft 48. The arrangement is similar to that disclosed in the copending applications (now patents) of Ness and Kojola previously referred to.

The separating, or dust-settling chamber Cs comprises a substantially cylindrical shell 58 located above the chamberC The rotatable shaft 48 extends upwardly through chamber. Cs and is journaled in a bearing 52 mounted on a cover 54. The cover 54 encloses the upper open end of chamber Cs, and forms a baflle with the gas scrubbing apparatus S, as specifically described in the previously referred to applications of Ness and Kojola. A scraper assembly 58 is mounted within chamber Cs. It is fixed to, and

rotates with shaft 48 during operation of the agitator assembly. Ag. Acetylene gas arising within chamber Cs is freed from heavy particles of dry lime; and. anysmall particles of solid material that do not separate within said chamber are removed from the gas as it passes through the scrubber S. The scrubber S is adapted to receive a continuous supply of fresh water from the main water line 38 through line 31; its rate of flow being controlled by a temperature-control valve. The upper portion of chamber C. is

'conduit 88 is fed through a ,valve 84 thence to passage82 which leads to the gas holder H A safety-relief vent 88 is provided in the cohduit 88, and an overflow 88 is connected to the scrubber 8. Both the vent 88 and overflow 88 are adapted to respectively release acetylene pressure and discharge excess water from the conduit 88 and the scrubber S without permitting the introduction of air to the generator.

The bottom of chamber Cu is provided with a lime withdrawal opening 18 adapted to open into the lime-seal hopper L. The lime-seal hopper L comprises an outer cylindrical shell I2 having an inlet I4 aligned with opening I8 in chamber Cs, and a lime outlet I8 located in its bottom wall. Thelime-agitator assembly or stirring means A1 is located within the hopper L and comprises a vertically disposed rotatable shaft I8, to which a lime-agitator frame 88 is rigidly secured. A lime-level indicator 82 is connected to the limeagitator frame 88 and its vertical movement is transmitted to a mercury switch 84 through a counter-weighted lever system 88.

The dry lime from hopper L is withdrawn by conveyor F1 at a rate which insures maintaining at all times sumclent lime within hopper L to provide an effective seal to prevent the entrance of air to the generator. The conveyor F1 is operated by the motor M1, which latter is controlled by the lime-level indicator 82 through the mercury switch 84. The lime-agitator frame 88 is ro-' tated by the motor Me. The details of the limeagitator assembly, lime-hopper assembly, and' lime-conveyor motor control are specifically described and claimed in copending application Serial No. 234,546, filed October 12, 1938, in the names of Charles Ness, Hugo V. Kojola, and Guy A. Dunn.

As previously stated, it is necessary to maintain Referring to Fig. 2 of the drawings, a threephase main line 88 is adapted to be completed or interrupted by a manually operable switch 82. The lime-seal agitator motor Ms is adapted to be connected across the main line 88 through another manually operable switch 84. A relay 88 is provided between the motor Ma and the line 88.

It comprises a magnetically operated switch 88 adapted to be closed upon energization of a holding coil I88 located in a circuit I82. The circuit I82 includes an overloadrelay I84 adapted to open switch 88 in the event motor Mn is overloaded, or fails to start for any reason. Additionally, circuit I82 includes a momentary contact push-button switch I88 which must be momentarily closedto complete the-circuit I82 to thereby close switch 88 and consequently start 1 motor M... After the switch as is closed, the cirprovided with an opening 58 through which the 78 cuit I82 remains complete even though push-button switch I88 opens, since a contact I88 of-switch 88 provides a holding circuit for the relay.

An alarm I I8 is connected across the main line 88 which sounds upon closing of switches-82 and 84. The circuit for alarm I I8 includes a normally closed electromagnetic switch I I2, the solenoid II4 of which is in circuit with motor Ms- Thus,

' product will result.

' relay upon completing the circuit of motor M. by closing switch l 88, solenoid I I4 is energized and opens switch H2 thereby shutting of! alarm I I8.

The lime-conveyor motor Ml must be in condition to operate when motor Ms starts in order to maintain the correct level of lime within limeseal hopper L. Thus, motor Mr is likewise connected across the main line 88 with a relay II8 between it and the line. Relay H8 is similar to relay 88 except that the circuit for its holding coil IE8 includes a normally open magnetically operated switch I28; the solenoid of which is in the holding coil circuit of switch 88 including contact I88. Additionally the circuit for holding coil M8 includes two manually operable normally closed switches I22, I28 which are safety devices adapted to be opened only when an emergency arises due to the improper action of the motor M1. The circuit for holding coil H8 also includes the mercury switch 84 which is opened. or closed in accordance with the level of the lime within hopper L as previously explained (see Fig. l)

A second alarm I28 is connected across the main line 88 through a mercury-switch I28 which latter is adapted to be operated with mercury switch 84, and also through a normally closed magnetically operated switch I38. The circuit for the solenoid I28 of switch I38 is connected across the line of motor Ml. Thus, starting of motor Ms closes switch I28 and completes the circuit for holding coil H8 so long as switches I22, I24 and 84 are closed. Under such conditions, motor Ml starts and switch I38 opens, thus stopping alarm I26 which has been ringing with alarm II8 when the main circuit 88 was completed. If, however, the lime level indicator 82 (Fig. 1) is below the normal lime level in hopper vL, both mercury switches 84 and I28 will be open, the motor M1 will not start, and alarm I26 will not sound. However, if the indicator 82 is above the normal lime level, switches 84 and I28 will be closed, motor M will start whereupon alarin I28 will be cut out by the opening of switch I38. It is to be noted that should motor M1 fail to start for any reason when it should, an overload relay I32 in circuit with holding coil II8 will open relay II8 without interfering with the continued operation of motor Ms, and upon opening of relay II6 alarm I26 begins to sound, thus indicating to the operator that the motor M1 is abnormal.

During periods of overhauling and maintenance work, it is often necessary to control the operation of motor M1 independently of the circuit through holding coil I88 of motor-Ms and thecircult through-mercury switch 84. Provision has been made for this contingency by providing a manually operable switch I34 in the circuit of holding coil II8 which shunts switches 84 and I28. The switch I34 is locked in open position during normal operation of the generator.

It is necessary tostart the' generator agitator motor Ms after the motors Ms and M1 have been started, and before feeding-carbide and water to The former step of this sequencethe generator. is necessary because otherwise the hopper L would be subjected to improper filling, thus impairing its sealing effect. The latter. step 01' this sequence is necessary because the carbide and water must be continuously agitated as they come'into contact, otherwise an improper lime The above sequential steps are insured by this invention. The motor M. is connected across the main line 88 through 9. I38 similar to relays 88 and H8, including a push-button switch I48. The circuit for the holding coil I38 of relay I38 is connected to line 88 through contact I88 of switch 88,'and until switch 88 is closed, closing of switch I48 will be ineffective to start motor Ma. A third alarm I42 is connected to the main line 88 through a normally closed magnetically operated switch I44, the solenoid circuit I43 of w ich is connected across the line of motor Ms. switch I48 will start motor M. and stop alarm I42 only if switch 88 for motor Ma is closed.

The feeding of carbide and water to the generating chamber Cs must occur-only when all other units of the plant are functioning or are in condition to function in accordance with the previously outlined sequence of operation. Furthermore, the feeding of carbide and water should be interrupted if any of the other units fail to function. Additionally, when the carbide feed valve V is closed due to the gas hell I! of gas holder Hg reaching its upper limit, the carbide feed motor Me and the operation of the water valve 38 should continue until the carbide screw housing 22 has been emptiedthey should then be stopped simultaneously. Furthermore, when the carbide feed valve V is opened due to the gas bell ll of gas holder Hg reaching its lower limit, the carbide feed motor Mo should be started some minutes before the water feed valve 38 is opened, because it has been found that betmagnetic switch I58, the solenoid I5I of which is connected in the circuit of motor Ma. Thus the starting of motor Mo requires motor M- to be operating. The circuit for coil I48 also includes a momentary push-button switch I52 normally not used during operation of the plant, and employed only during periods of maintenance and repair. In order to insure stopping of the motor Me in the event the lime-seal conveyor motor M1 stops, the circuit for holding coil I48 also includes a normally closed. magnetic switch I54, the. solenoid I53 of which is connected to the circuit of alarm I26. The latter alarm circuit includes magnetic switch I38 having its solenoid I28 connected across motor M1. Therefore, magnetic switch I54 opens if motor Ml stops, thus effecting the stopping of motor Me.

The circuit of coil I48 also includes a camoperated switch I58, forming a part of the timing control T. This circuit extends from control T to line 88 through the closed portion I12 of switch I88 and the contact I88 of relay 88, thereby requiring motor Ma to be operating as a prerequisite to the operation of motor Me.

The solenoid for water valve 38 is connected across the main line 88 through a normally open magnetic switch I58, the holding coil I81 of which is connected across the circuit of the carbideieed motor Mo. Additionally, the circuit for valve 38 extends through a cam-operated switch I88, forming another part 01' the timer T, thence Thus, closing of ing unit I64. In the present embodiment of the invention, shaft I62 is gearedto complete one revolution in ten minutes. The timing motor MI. is connected across the main line 90 through a two-way oscillatable switch I 66 and through the switch 94. Oscillatable motion is imparted to the switch I66 by the action of valve V which action in turn is controlled by the upper and lower limits of the gas bell I1 of gas holder He. A pair of cam-operated switches I68, I mounted on shaft I62 are alternately adapted to start the timing motor Mt, and maintain its continuous operation for a definite time limit, depending upon the position of oscillatable switch, I66. Thus, one side of the timing motor Mt is connected to the main line 90 through the switch 94, while the other side of said motor is connected to a common point I65 on the two-way switch I66. One side I61 of two-way switch I66 is connected to' line 90 through the cam-operated Cg. The extent of portion- Y is suflicient to in-' switch. I 10. The other side I69 of two-way switch I66 is connected to one pole of switch I68,

the other pole of which is wired to main line 90. All of the switches I56, I60, I68 and I10 are provided with segmental contact portions represented by the plain portions 01' the switches. The arrangement and design of the segmental contact portions of switches I68 and I 10 are such that each is alternately adapted to complete the circuit of motor Mt for one-half a revolution of shaft I62. As the one switch opens, the other closes. Thesegmental v contact portions of switches I56 and I60 are so arranged that when switch I56 is in initial position to complete the circuit for the holding coil I48 and relay I46 of motor Me, the circuit of solenoid valve 38 through switch I60 is still open-{and the latter closes, commencing the feed of water to chamber Cg, after a few minutes of operation of the carbide feed motor Mc.

Assume'that the gas bell I1 of gas holder Hg is in its lower position and that it is desired to start the generating plant. Switches 92 and 94 in the main line 90 are first closed. This causes alarms IIO, I26 and I42 to sound. Push-button switches I06 and I40 are closed in the order named thus starting lime-agitator motor Mt, lime-conveyor motor M1, and generator agitator motor Me. in the order named, and stopping the alarmsIIO, I26 and I42. 'Since the gas bell I1 is at its lower limit, valve-Vwill open due to the action of lever I5 on lever I3 thus causing switch I66 to assumev the position shown in solid lines, and switches I56, I60, I68 and I10 will be in the position shown in Fig. 2 of the drawings. Thus it is apparent that the circuit for motor MttO mainline 90 is completed through switch I10, and motor ,Mt drives shaft I62 in the direction of the arrow X for one-half revolution until the circuit is broken by the opening of switch I10. While shaft I62 moves .through its acetylene, and the gas bell "arrives at its upper .limit thus moving three-way.valve I I to direct air under pressure into line I6 of cylinder I4 and thereby effecting the closing of valve V.

The motion of valve V in closing moves switch 4 I66 to its position in dotted lines thus re-starting timing; motor Mt by completing its. circuit through switch I69. Since carbide feed valve V is now closed, a portion Y of the segmental contacts of switches I56 and I60 maintains the operation of carbide feed motor M0 and the continuous feed of water to the generating chamber sure the operation of motor Me and valve 39 until all carbide within conveyor housing 22 has been delivered to chamber C: and completely reacted with water to form acetylene. The operation of motor Mt continues after the switches I56 and I60 open, to complete a single revolution of shaft I62 thereby re-setting the time control device T in position to re-commence its cycle of operation. When the gas within the gas holder Hg has been consumed, and the bell I1 falls again to its lower position, valve V is again opened thus moving switch I 66 again to its position shown in solid lines andthereby starting timing motor Mt on another cycle of its operation.

Closing and opening of valve V, and consequently stopping and starting motor MO and valve 38 is continued so long as the consumption of acetylene gas causes the bell I1 t move between its lower and upper limits. Dur g these inter-' ously, and the lime-conveyor motor Ml operates intermittently in accordance with the level of the half revolution, the circuit for motor Me is com- I pleted through switch I56 for a definite time interval before the circuit for valve 38 is completed through switch I60. At the end of this half revolution of shaft I62, the segmental contact portions of switches I66 and I10 assume the position of switches I66 and I10, wherein switch' I68 is in position to complete the circuit of motor Mt. except that two-way switch I66 must bemoved to its dotted line position. The two other switches I56 and I60 then assume the position of switches I56, I60. In the position of switches I56, I60, I68 and I10, generation of acetylene continues until the gas holder Hg is filled with lime within hopper L.

When it is desiredto shut down the generating plant for anextended period, say for overnight, the operator need only close the valve V by manipulating the manually operable valves I 9,

2 I, and 23 in the air lines I-6 and I8. This action sets the timing device T into operation to stop motor Mo and close water valve 38. Then the operator opens portions I12 and I14 of pushbutton switches I06 and I40 thereby stopping motors Ms, M1 and Ma in the order named and causing the alarms IIO, I26 and I42 to sound. Opening of switches 92 and 94 causes the alarms to stop sounding, and the plant is completely shut down. 1

From the foregoing description, it is apparent that a semi-automatic electrical control circuit has been provided for an acetylene generating plant wherein a definite sequential order of starting and stopping, and of timing the operation of various units of the plant has been provided.

The previously described generating plant may be provided with a completely automatic electrical control system which wiil follow a similar sequential order of operation as set forth in connection with the semi-automatic electrical control system of Fig. 2. i

Fig. 3 of the drawings illustrates a wiring diagram for eflecting complete automatic control of the various electrically operated units of the generating plant. Due to the rather complex nature of the circuit, Fig. 3 includes along its sides, a vertically arranged set of indices for facilitating describing the circuit.

The circuit of Fig. 3 includes in line, atime cycle controller T'- comprising a motor Mt geared to a shaft 200 to which are fixed eight controller cam switches, the cam surfaces 01' which are shown in developed'form in Fig. 4. The motor Mt may drive shaft 200 at any desired rate, and in the present embodiment, it effects a single revolution of shaft 200 in about twenty-five minutes. During a single cycle of revolution, the eight switches on shaft 200 are adapted to set into operation and stop the various operating units of the generator plant in accordance with any predetermined timedgsequence. Briefly, the accomplishments of this circuit are as follows:

As the carbide feed valve V opens when the bell ll of gas holder H reaches its lower limit, timing motor Me is set into motion. The eight controller switches on shaft 200 may be set to successively start the various operating units of the generator plant in accordance with a determinedsequential order and predetermined timed relation. While the specific timing of the starting and stopping of the various units may vary within appreciably wide limits, the following arrangement has been found to be completely satisfactory, and is given merely as an illustration of one specific arrangement of the cams on shaft 200. It is to be understood that other timing relations may be effected by adjusting the eight cams on shaft 200. According to one specific arrangement of the cams on shaft 200, the following schedule will prevail:

a. Ten seconds after the motor Mt begins to operate, the lime-agitator motor Ms will be started, and the lime-conveyor motor M1 will be operated in a manner similar to that previously explained to maintain the lime level in hopper L at a definite height.

b. Ten seconds later, the generator agitator motor M. will be set into operation.

0. One and one-half minutes later, the-carbide feed motor Mo will be set into motion.

11. One and one-half minutes later the valve 3d will be opened to admit water to the generating chamber C e. One minute later, the motor Mt stops.

Upon completion of the foregoing schedule, it is apparent that the generating plant is set into operation to generate acetylene. When the gas bell I! of gas holder Hg becomes filled with gas and reaches its upper limit, valve V will be closed as previously described. The closing of valve V ire-starts the motor Mt to complete the operating cycle of the timer control T' to thereby shut down the generating plant as follows:

a. Two minutes after motor Mt has been restarted, carbide feed motor Me will be stopped.

b. One-half minute later, solenoid waiter valve 38 will be closed.

c. Seventeen minutes later, generator agitator motor Ma will stop.

11. One-quarter minute motor Ml will stop.

e. Que-quarter minute later, the motor Mi will stop.

As the motor Mt finally stops, the eight switches on shaft 200 will be in position to repeat the above-described complete cycle of setting the generator plant into operation and stopping the same.

Certain safety features are combined in the circuit of Fig. 3 for the following purposes:

1. If motor Ms stops for any reason, the carbide feed motor Me will stop, valve 30 will close, and an alarm will sound.

2. If motor Ma should stop for any reason, the motor Mo will stop, valve 38 will close, and an alarm will sound.

later, lime-agitator aaeaess 3. If the motor Mo should stop for any reason, valve 38 will close and an alarm will sound.

4. If the motor M1 fails to start when the lime level in hopper L reaches its upper limit, the motor Me will stop, valve 30 will close, and an alarm will sound.

Referring to Fig. 3, and the index' on the sides of the drawings, motors M, Ms, Me and M1 (line 34) are shown connected across the main line 90. The automatic control system is placed into operation by closing circuit breakers 202, 204 (line 3|), and circuit breaker 206 (line 28). Closing the circuit to transformer 200 (line 21) impresses 1103 volts across the lines 2). Relay 2l2 (line 28) has been energized by closing circuit breakers 202 and 204. It comprises two normally open contacts 2l2a, 2|2b (lines I and I9 respectively), and a normally closed contact 2i2c (line 9). .Upon energization of relay 2l2, therefore, contacts 2i2a,.'2l2b close, and 2l2c opens. .When contact 2i2a (in line i) closes, a red signal light 2l2d (in line i) lights indicating to the operator that the control system is energized and ready for operation.

When the bell ll of gas holder Hg drops to its lower limit due to acetylene consumption, limit switch 2i4' (line 2) closes, thereby energizing solenoid valve 2; (line 2), energizing relay 2IB (line 4) and illuminating green light 220 (line 3). Relay 218 comprises normally open contact 2l8a (line 3), which will close upon energization of said relay, and serve as an interlock to maintain solenoid valve 2 l6 (line 2) energized after switch 2M opens when the bell i'i begins to rise.

Solenoid valve 2l6 (line 2) controls the flow of compressed air to cylinder 14 through lines it and i8 (see Fig. 1) and when energized, valve 21s directs this air to line l8 thereby forcing carbide feed valve V to its open position. This movement of valve V trips the double-pole, double-throw limit switch 222 (line M) to its dotted line" position, thus completing the circuit of motor Mt through normally closed, mechanically openable switch 224, whereupon timing motor Mt begins to operate, and a blue signal light 226 (line l2) becomes illuminated.

About ten seconds after motor Mt starts, cam 228 (line i4) on shaft 200 closes switch 230 (line 22) through a mechanical intercontrol 232 shown in dotted lines. Closing of switch 230 energizes a holding coil of an automatic motor-starter-relay 234 (line 23), Relay 234 includes contacts 234a (line 32), and energization of the coil of relay 234 closes these contacts 234a to-set motor Ms into operation, Motor starter relay 234 also includes normally open interlock contact 2341) (line 25) as well as normally closed interlock contacts 234a and 234d (lines 6 and 8 respectively), the former of which closes and the latter two of which open when the holding coil of relay 234 is energized. Relay 234 also includes thermal overload relays 234a and 2341 (line 23) I When motor starter relay 234 (line 23) becomes energized, interlocked contact 234b (line 25) is closed. Therefore, when the level of the lime in the lime hopper L (see Fig. 1) reaches its upper limit, switch 84 (line 25) will close, and automatic motor starter. relay 23l (line 24) will be energized. Relay 23| includes contacts 23la (line 32) which will close upon energization of relay 23l to thereby start line conveyor motor M1. Additionally, the relay 23i includes normally closed contact 2'3ib (line 25) which will be opened upon the energization of relay 23 i When the line level within the hopper L has been lowbide feed motor Me (line 34).

includes normally closed interlock contact 258b ered to its lower limit, switch mm 25) will be opened, thereby shutting of! motor M1.

Twenty seconds after motor -Mz begins to operate, cam 236 on shaft 288 closes switch 238 energization of the holding coil of relay 242, contact'242b closes and contacts 242c and 24211 open. Relay 2 is provided with thermal overload relays 242e and 242) (line 2|).

Thirty-five seconds after motor Mt starts.

' cam 244 on shaft 288 closes switch 246 (line 1) through interlock 248. Thereafter, alarm 258 (line 1) will sound, and the amber signal light 2 (line 5) or the green signal light 243' (line 6) will be illuminated if the holding coils of the automatic motor starter relay 242 (line 2|) or 234 (line 23) respectively become de-energized.

Approximately one minute and fifty seconds after motor Mt starts, cam 252 on shaft 288 closes switch 254 (line l8) through the mechanical interlock 256. Closing of switch 254 energizes the holding coil of a third motor starter relay 258 (line l8). The relay 258 includes the main motorcontacts 258a (line 32) of the car- Relay 258 also (line l9) which opens upon energization of the holding coil of said relay. It also includes two thermal overload relays 2580, 258d (line l8) About two minutes and five seconds after motor Mt starts, cam 268 on shaft 288" (line 14) closes switch 262 (line l6) through the interlock 264 shown in dotted lines. Thereupon relay 266 (line IE) will become energized and a white light 268 (line 28) will become illuminated if automatic starter relay 258 shouldbecome de-.

energized due to its thermal overload relays 2580 or 258d -(line l8) opening, or to its holding coil burning out. Relay 266 includes a normally closed interlock contact 2660 (line l5) for a purpose to be described later. Additionally, relay 266 includes normally open contact 26617 (line l8), and upon the de-energizing of relay 258, contact 26% will close causing alarm 258 (line 1) to sound.

About three minutes and twenty seconds after motor Me starts. cam 218 on shaft 288 operates to close switch 212 (line l1) through the interlock 214- shown in dotted lines. Closing of switch 212 energizes the solenoid watervalve "38 (line l6), causing it to-open and feed water to the generating chamber Cg. (Fig.1.) Thereupon, if relay 258 becomes de-energized, contact 266a will open thereby closing the valve 38 (line l6) and shutting off the water supply to chamber Cg. (Fig. 1.) a

Shortly after switch 212 '(line I 1) 'is "closed, cam 216 on shaft 288 operates to close switch 218 (line-l5) through the interlock 288 shown in dotted lines.

Four and one-half minutes after motor Mt starts, cam 282 on shaft 288 operates to open normally closed switch 224 (line H) through the mechanical intercontrol 284 shown in dotted lines, thereby stopping the motor Mt after the entire generating plant of Fig l has been put into operation. I I

When the bell l1 of the gas holder Hg reaches its upper limit, normally closed switch 2" (line 4) will be opened by the action of levers l5 and I3 (Fig. 1). Opening of switch 211 causes the de-energizing of relay 2l8 (line 4), which in turn will open contact 2l8a (line 3), The green signal light 228 (line 3) will then 'be extinguished, and the solenoid valve 2| 6 (line 2) will be deeenergized. De-energization of the solenoid valve 2l6 causescompressed air to be admitted to pipeline l6 of cylinder l4 to thereby eifect closing of the carbide feed valve V (see Fig- 1). The closing motion of valve V will cause limit switch 222 (line M) to trip to the solid line position and since-switch 218 (line l5) has been previously closed, the motor Mt of the time controller T' will be re-started, the

blue signal light 226 (line l2) will be extin-- guished, and the amber signal light 298 (line l5) will be illuminated. 1

One and one-half minutes after the motor Mt has been re-started, cam 268 on shaft 288 will open switch 262 (line l9). After an additional one-half minute interval, cam 252 on shaft 288 (line l4) will open switch 254 (line l9).

Openingoi' switch 254 causes the de-energization of automatic starter switch relay 258 (line I8) thus contacts 258a (line 82) of the relay258 will open and stop the carbide feed motor Me (line 84).

Two and one-half minutes after the re-starting of motor Mt, earn 218 on shaft 288 will open switch 212 line l1) thereby de-energizing the solenoid water valve 38 (line l6), effecting its closing and thereby shutting off the flow of water to the reaction chamber Cg (see Fig. l).

Nineteen and one-half minutes after the restarting of motor Mt, cam 244 on shaft 288 will cause the opening of switch 246 (line 1), thus the circuit to the alarm 258 in line 1, and the amber and green signal lights 2 and 243 (lines 5 and 6 respectively), will be cut out thereby preventing the sounding of alarm 258 (line 1) or s on shaft 288 will close switch 224 (line l8), and

simultaneously-therewith cam 236 on shaft288 will open switch 288 (line 22). The opening of switch 238 (line 22) causes the de-energization of automatic motor starter relay 242 (line 2|), and the main contacts 242a (line 32) of the motor M, (line 34) will be opened causing this motor to stop, thus stopping the generator agitator assembly A; (see Fig. 1). Likewise, the de-energization of relay 242 (line 2 I) will efiect the opening of theinterlock contact 242b (line H) and the closing of interlock contacts 2420, 242d (lines 5 and 1 respectively).

One-half minute after the opening of switch 246 (line 1), or twenty minutes after the restarting of motor M cam 228 on shaft 288 will cause the opening of switch 238 (line 22), thus de-energizing automatic motor starter relay 234 (line 23'). The de-energization of relay 234 will cause the opening of switchesi234a (line 32) of motor Ml, thereby. stopping lime agitator as sembly A1 (see Fig. 1). Additionally, the deenergization of relay 234 (line 23) will effect the opening of contact 2341) (line 26) and the closof contacts-234c, 234d (lines 6 and 8 respectively).

The generating plant of Fig. 1 will.then be completely shut down. Twenty and one-quarter minutes after the re-starting of motor Mt", cam 216 on shaft 200 will open switch 218 (line l6) causing the motor Mt to stop, and extinguishing the amber signal light 290 (line IS).

The time controller T, as well as all 01' the electrically operated units of the generating plant of Fig. 1, will then have gone through a complete cycle of operation, and will remain idle until the bell H of the gas holder Hg drops to its lower operating limit due to the consumption of acetylene gas thereby closing switch 2 (line 2) which will begin anew cycle by starting the .224 at 65, and to effect closing of switch 224 at 355 of the revolution of shaft 200. Cam 216 is adapted to maintain a closed-circuit through motor Mt and switch 218, whenswitch 222 is moved to its solid line position by the filling of the gas latter will sound in the event any of these relays become de-energized other than in the natural sequence of the plant operation, or by the tripping of circuit breaker 204 (line 30). For example, ii the relay 242 (line 2|) should become tie-energized other than in its natural sequence, contacts 242e, 242d (lines 6 and 1 respectively) will close, thus causing alarm 260 (line 1) to sound, and amber light 24| (line 6) to become illuminated. The alarm 260 may be cut out by momentarily closing push-button contact 292 (line 9), which will efiect energization of relay 294 (line l0), and the illumination of red signal light 298 '(line 9). Energization of relay 294 (line l0) causes the closing of normally open contact 294a (line l0) and the opening of normally closed contact294b (line 1), thus cutting out alarm 260. Inasmuch as contact 2940 (line l0) has been closed by the energization of relay 294, red signal light 296 (line 9) will remain illuminated and contact 2941) (line 1) will remain open. This condition will prevail until relay 242 (line 2|) holder Hg, for a sufiicient length of time to stop the various units of the plant in a predetermined timed sequence. Cam 216, therefore, is set to close at 60, and to open at 360the 300 of the revolution of shaft 200 requires approximately twenty and one-half minutes within which to stop the generator units.

The previously described timed sequential order of starting and stopping the various units is obtained by setting the remaining cams on shaft 200 as follows:

Cam 228-closes at 3opens at 357. Cam 238-closes at 6-opens at 354. Cam 244closes at 9-opens at 351. Cam 252--closes at 25-opens at 95. Cam v210-closes at 45opens at 100. Cam 260--closes at 30opens at 90".

"Referring again to the circuit for the limeconveyor motor M1, and when switch 84 (line 25) is closed, if automatic starter relay 231 (line 24) should either fail to become energized orshould become ale-energized as a result of its holding coil burning out or its thermal overload relays 2310, 231d (line 241) tripping, interlock contact 23|b (line 25) will close. This will cause the blue signal 233 (line 26) to become illuminated and the time relay 235 (line 25) to become energized. Relay 235 includes a normally open delayed closing contact 235a (line I) which will be closed upon energization of relay 235. Closing of switch 235a (line II) will cause the sounding of alarm 250 (line 1) and the energization of the relay 231 (line H). Relay 231 includes normally closed contact 231a. (line 19), which opens upon the energi'zation of relay 231, thus stopping the feed of carbide and water to the reaction chamber Cg (see Fig. 1).

From the foregoing description of the intercontrol between the automatic motor starter relays 258 (line I8). 242 (line 2|), 234 (line 23), and 231 (line 24) and the alarm 250 (line 1), the

has been repaired and becomes energized again, at which time the contacts 2420, 242d (lines 6 and 1 respectively) will be opened.' Opening of contact 242d (line 1) will cause the de-energization of relay 294 (line 10), thus opening contact 294a (line l0) and closing contact 2941) (line 1). The opening and closing of these last-mentioned contacts extinguishes the red signal 296 (line 8) andplaces the alarm 250 (line. 1) in condition to sound the next time that any of the automatic motor starting relays above-mentioned become de-energized other than in the natural sequence of operation of the entire generating plant.

For the purpose of permitting the operator to manually control any item of the various electrically operated control units of the generating plant, a series of push-button switches is provided throughout the electrical circuit, and these switches are located at convenient places so that the operator may conveniently open and close any desired circuit. Thus, push-button switch 298 (line 21) provides a means for quickly stopping all moving parts of the generator; push- ,button switch 300 (line 24) provides a means for starting or stopping the lime conveyor motor M1 at any time; push-button switch'302 (line 23) provides means for starting or stopping the lime agitator assembly motor M, at any time; pushbutton switch 304 (line 2|) provides a means for starting or stopping the generator agitator paddle assembly motor Ma at any time; push-button switch 306 (line l8) provides a means for starting or stopping the carbide feed motor Me at any time when the generator agitator paddle assembly motor Ma is in motion; push-button switch 308 (line l6) provides-a means for starting or stopping the solenoid water valve 38 (line H5) at any time when the motor Ma is in operation; push-button switch 292 (line 9) provides a means for shutting of! alarm 250 (line 1) after it has sounded; pushbutton switch 3|0 (line 4) provides a means for starting or stopping the generating plant regardless of the position of the bell ll of the gas holder Hg; and push-button switch 3|2 (line l6) provides a means whereby the motor Me. for the generator agitator assembly may be kept in operation at all times by making it independent of the automatic control system.

From the foregoing description of the electric circuit disclosed in Fig. 3 of the drawings, it is apparent that a fully automatic electric control system has been provided for the generating plant of'Fig. l, which system'is adapted to initiate .control system disclosed in Fig, 2. I

Although the various features of a specific type of acetylene generating plant and electrical control systems therefor have been shown and described in detail to fully disclose two embodiwithin said generating chamber; means for collecting the acetylene gas; means for collecting the dry residue produced by the reaction of the carbide and, water; electrically operated means for agitating the collected residue; electrically operated conveying means for removing the dry residue from the residue collecting means at a rate which will automatically retain sufficient residue within said residue collecting means at all times to provide a seal therein; and electric interlocking control circuits for all of said electrically operated means for insuring the starting of the respective electrically operated means in accordance with a predetermined sequential order.

2. An acetylene generating plant as claimed in claim 1, in which said electric interlocking circuits comprise automatic starter switch relays for all of said electrically operated means, the holding coil circuits of said relays being interlocked in a manner to require starting of each of said electrically operated means in accordance with a predetermined sequential order.

3. An acetylene generating plant as claimed in claim 1, in which said electric interlocking circuits comprise automatic starter switch relays for all of said electrically operated means, the holding coil circuits of said relays being interlocked in a manner to render the operation of certain of i said electrically operated means dependent upon theoperation of certain other of said electrically operated means.

4. An acetylene generating plant including, in combination, an acetylene generating chamber; electrically operated means for feeding calcium carbide into said generating chamber; .electrically operated means for feeding controlled amounts of water into said generating chamber; electrically operated means for agitating the mixture of materials, within said generating chamber; means for collecting the acetylene gas;

means for collecting the dry residue produced by the reaction of the calcium carbide and water;

electrically operated means for agitating the predetermined sequential order; separate motors for operating the residue-agitating and residueconveying means, and said electric interlocking circuits including automatic starter switch relays for such motors, the holding coil circuit of the relay for the residue-agitator motor including a normally open push-button switch and a solenoid, the holding coil circuit of the relay for the residue-conveyor motor including a normally open switch adapted to be closed upon energization of said solenoid, and a level control switch, the opening and closing of which is dependent upon the level of residue within said residue-collecting means, whereby the closing of said push-button switch starts the motor for said residue-agitating means, and the motor for said residue-conveying means automatically starts and stops in accordance with the level of the residue in said residue-collecting means only if the motor for said residue-agitating means is operating.

5. An acetylene generatingplant including, in combination, an acetylene generating chamber; electrically operated means for feeding calcium carbide into said generating chamber; electrically operated means for feeding controlled amounts of water into said generating chamber; electrically operated means for agitating the mixture of materials within said generating chamber; means for collecting the acetylene gas;

means for collecting the dry'residue produced by the reaction of the calcium carbide and water; electrically operated means for agitating the collected residue; electrically operated conveying means for removing the dry residue from the residue-collecting means at a rate which will auto- 'matically retain'suflicient residue within said residue-collecting means at all times to provide a seal therein; electric interlocking control circuits for all of said .electrically operated means for insuring'the' starting of the respective electrically operated means in accordance with'a predetermined sequential order; separate motors for tor including a normally open push-button switch,

and the holding coil circuit of the relay for the generating chamber agitating motor including a normally open push-button switch, said lastmentioned holding coil circuit being interlocked through said last-mentioned push-button switch with the holding coil circuit of the relay for the residue-agitating motor, whereby the motor for the residue-agitating means must be started before starting the motor for the generating chamber agitating means. a

6. An acetylene generating plant including, in combination, an acetylene generating chamber; electrically operated means for feeding calcium carbide into said generating chamber; electrical- 1y operated means for feeding controlled amounts of water into said generating chamber; electrically operated means for agitating the mixture of materials within said generating chamber; means for collecting the acetylene gas; means for collecting the dry residue produced by the reaction of the calciumcarbide and water: electrically operated means for agitating the collected residue; electrically operated conveying means for removing the dry residue from the residue-collecting means at a rate which will automatically retain sufficient residue within said residue-collecting means at all times to provide a seal therein: electric interlocking control circults for all of said electrically operated means and a level-control switch,'.the opening and closing of which is dependent upon the level of residue within said residue-collecting means: and

the holding coil circuit of the relay for the generating chamber agitator motor including a normally open push-button switch, said last-mentioned holding coil circuit being interlocked through said last-mentioned push-button switch with the holding coil circuit of the relay for the ,-residue-agitator motor, whereby the motor for the residue-agitating means must be started and the motor for the residue-conveying means must be in condition to start before starting the motor for the generating chamber agitating means. the operation of the residue-conveyor motor depending upon the level of the residue within said residue-collectins means. a

'1. An acetylenegenerating plant including, in combination,- an acetylene generating chamber; electrically operated means for feeding calcium carbide into said generating chamber; electrically operated means for feeding controlled amounts of water intosaid generating chamber; electrically operated means for agitating the mixture of materials within said generating chamber: means for collecting the acetylene gas; means for collecting the dry residue produced by the reaction of the calcium carbide and water: electrically operated means for agitating the collected residue; electrically operated conveying means for removing the dry residue from the residue-collecting means at a rate which will automatically retain sufllcient residue within said residue-collecting means at all times to provide a seal therein; electric interlocking control cir-' cuits for all of said electrically operated means for insuring the starting of the respective electrically operated means in accordance with a predetermined sequential order; separate motors for operating the residue-agitating, the residueconveying, and the generating chamber agitating means: said electric interlocking circuits including automatic starter switch relays for such motors, the holding coil circuit of the relay for the residue-agitator motor including a normally open push-button switch and a solenoid, the holding coil circuit of the relay for the residue-conveyor motor including anormally open switch adapted to be closed upon energization of said solenoid,

and a level control switch, the opening and closing of which is dependent upon the level of residue within said residue-collecting means; the

aaoaoss ing solenoid-operated switches in the circuits of said motors, the circuit of the signal for the residue-conveyor motor including a second switch adapted to be opened and closed in accordance with the level of the residue within said residuecollecting means, whereby the motor for the residue-agitating means must be started and the motor for the residue-conveying means must be in condition to start before starting the motor for the generating chamber agitating means, the operation of the residue-conveyor motor and the signal therefor depending upon the level of the residue within said residue-collecting means.

, 8. An acetylene generating plant including, in

combination, an acetylene generating chamber; electrically operated means for feeding calcium carbide into said generating chamber; electrically operated means for feeding controlled amounts of water into said generating chamber; electrically operated means for agitating the mixtur'eof materials within said generating chamber; means for collecting the acetylene gas;

means for collecting the dry residue produced by the reaction of the calcium carbide and water; electrically operated means for agitating the collected residue; electrically operated conveying means for removing the dry residue from the residue-collecting means at a rate which will automatically retain sufiicient residue within said residue-collecting means at all times to provide a seal'therein; electric interlocking control circuits for all of said electrically -operated means for insuring the starting ofthe respective electrically operated means in accordance with a predetermined sequential order; separate motors for operating the residue-agitating means. the residue-conveying means, the generating chamber agitating means, and the carbide feeding holding coil circuit oi. the relay for the generating chamber agitator motor including a normally open push-button switch, said last-mentioned holding coil circuit being interlocked through said means: said interlocking circuits including automatic starter-switch relays for such motors. the circuit for the holding coil of the relay for the generating chamber agitator motor including a normally open push-button switch which is interlocked with the relay for the residue-agitator motor: and the circuit for the holding coil of the relay for the carbide feed motor including two solenoid switches, the solenoid of one of which is interlocked with the circuit of the generating chamber agitator motonand the solenoid of the other of which is interlocked with the residueconveyor motor, said circuit for the holding coil of the relay for the carbide feed motor also including a time-operated switch.

9. An acetylene generating plant including, in combination, an acetylene generating chamber; electrically operated means for feeding calcium carbide into said generating chamber; electrically operated means for feeding controlled amounts of waterinto said generating chamber; electrically operated means for agitating the mixture of materials within said generating chamber; means for collecting the acetylene gas; means for collecting the dryresidue produced by the reaction of the calcium carbide and water; electrically operated means for agitating the collected residue; electrically operated conveying means for removing the dry residue from the residuecollecting means at a rate which will automatically retain suflicient residue within said residuecollecting means at all times to provide a seal therein; electric interlocking control circuits for all of said electrically operated means for insuring the starting of the respective electrically operated means in accordance with a predetermined sequentlal order; separate motors for op erating the residue-agitating means,'the residuecollecting the dry residuerproduced by the reconveying means, the generating chamber agiactionof the calciumcarbide and water; electating means, and the carbide feeding means; I trically operated means for agitating the collect-- and a solenoid-operatedwater valve for operated residue; electrically-operated conveying means King the water feeding means: said interloc I g for removing the dry-residue from the residuecircuits including automatic starter switch ecollecting means at a rate which will automatilays for such motors, the circuit for the holding cally retain 'sufllcient residue within said residuecoil of the relay for the generating chamber asitin m ns at ll times Pm'vid'e a seal tator motor including a normally open 'push-buttherein; electric interlocking control circuits for ton switch which is interlocked with the relay all of said electrically operated means for insurfor the residue-agitator motor; the circuit'ior ing the starting of'the respectiveelectricaily optheholding coil of the relay for the carbide erated means in accordance with a predetermined "'f feed motor including two solenoidiswitches, the sequential order; separate motors for operating solenoid of one of which is interlocked with the the residue-agit ing m s, the residue-concircuit of the generating chamber agitator motor. y h means. the fi fl g chamber agitatingand the solenoid of the other of which is intereans, and the car d means; a $016- locked with the circuit of the residue-chnveyor hold-operated water valve for ope a ng the wamotor, said circuit for the holding coil of the fe din means; said interlockin c s inrelay for the carbide feed motor also including l h automatic Starter Switch e ys for such a time-operated switch; and the circuit for the 2 motors-the circuit for the holding coil of the. re-

solenoid of said water valve including a solenoidlay,for the generating ch m er itator motor operated swi'tch, the solenoid of-which is interincluding 8 9 3 Op n Pu hu ton switch locked with the circuit for the carbide feed mowhich s interlocked wi the relay r the resitor, 'the circuit for the solenoid of said water -a a t the i u t f r th ho di l e also including a time-operated Switch 2 coil of the relay .for the carbide feed motor in- 10. An acetylene generatingplant asv iaimed i cluding two solenoid switches, the solenoid of one claim 1, in which said interlocking circuits of which is interlocked with the circuit of the clude.a timing device adapted to be set into 09- fi' g ch mber agitator motor, and the soeration upon the filling and emptying of th lenoid of the other 01 which is interlocked with acetylenereollecting means, and adaptedtto start the -G BY 11101501, Said circuit for he and stop said carbide and water-feeding means holding i of t e relay for the carbide e in accordance with a predetermined timed rela- 3150, including rotatable p a d on r. switch; said time-operated switch being adapted 11 An acetylene generating to be Started the 0f the acetylenecombination, an acetylene generating chamber: collecting me and to rotate through apart of electrically operated means for feeding calcium one revolutioniflhd h to Stop. and to plete carbide into said generating chamber; electrih circuit for: the calfbide feed 11101501 e y in n operated means f r feeding controlled advance,;of completing the circuit for the soleamounts f water sa generating chamber; noid of said water valve, said time-operated electrically operated means for agitating the mix-' 40 Switch being pted to be restarted when said ture of materials within said generating chamber; acttylene'coneiltmg ns is filled to complete means for collecting the acetylene gas; means revolutmn, to simultaneously p e carior collecting the dry residue produced by the rebide feed r. nd to shut ofi said water valve action of the calcium carbide and water; elecafter a tqe ermined interval of time. trically operated means for agitating the collect- 4 An acetylene genel'flting Plant comprisil'lig; ed residue; electrically operated conveying rheans in combinationy-an acetylene e ator having-a for removing the dry residue from the residue- Yea-i911 chamber; means e in calcium contacting means at a rate which Wm auto ti carbide and water into said reaction chamber; cally retain suflicient residue within said residuemeans agitating the mixture of materials collecting means at all times to provide a seal 5 Withm'said chamber; a a trol system for therein; electric interlocking control circuits for d Plant comprising elec interlocking means all of said electricallyoperated means for insurinsuring the Starting 01 the agitating means ing the starting of the respective electrically P110! to the starting 01 the feeding ea s, and operated means in accordance with a-predeterinsuring the pp g of the feeding means mined sequential order; a motor for operating the 5 Prior to the Stopping v the g t t means. carbide-feeding means; a solenoid-operated 'wa- An acetylene l h Plant as claimefi ter valve for operating said water-feeding in claim in which Said P t is so Provided means; the interlockingcircuits including an auwith means collecting h y residue P tomatjc e switch relay for t bi feed duced from the reaction of the calcium carbide motor, and also including the'solenoid of said and r. d Stirring means for agitating the water valve; and flme 0peraf,ed switch tcollected residue; and in which said control sysed to be set into operation by the action 0! the tem includes Ill/8811B 0 insll g thestart 0f acetylene-collecting means and adapted to coin- Said Stirring means i the St rt g 0! the plete the circuit for the carbide feed motor relay e g and agitat hsin advance of completing the circuit for the 35 An acetylene neratin P t as claimed solenoid of said water valve. in laim 13 in which said plant is also provided 12. An acetylene generating plant including, W1 h fi1 ansf r collecting the dry" residue. Dru?" combinatioman acetylene generating chamber; i y the reaction of the --caicium carbide electrically operated means for feeding calcium I a d water, -S i means 0h 'fl at' the oblcarbideinto said generating-chamber; electricallected residue, means for withdrawing the resi-v ly operated means for feeding controlled amounts due from the collecting means when the residue 0! water into said generating chamber; electritherein rises above a predetermined level, and

cally operated means for agitating the mixture means for insuring the starting oi thej;stirring oi materials within said generating chamber; and withdrawing means before the starting or means for collecting the acetylene gas; means for 76 the feeding and agitating means, the operation of said withdrawing means depending on the height of the residue in. the collecting means.

16.. In an acetylene generating plant having a residue agitating device, aresidue-conveying device, and-separate motors for driving said devices; electric interlocking circuits for controlling the operation ofsaid plant comprising in combination, a timing device; an automatic starter switch relay adapted to be energized-by the action of, said timing device to'thereby start the motor for said residue-agitating device; an

automatic :starter switch relay adapted to be energized in accordance with the amount of means for. feeding calciumcarbide and water into a generating chamber, means for agitatingthe mixture of materials-within the generating chamber,'and separate motors for driving said means, electric interlocking circuits for controlling-the operation of said plant comprising, in

combination, a timing device; automatic starter switch relays adapted to be energized by the.

action of said timing device tothereby start the motors for the agitating'means and the carbide and water-feeding means, the circuits for said relays including 'contacts'adapted to be closed and opened m a predetermined sequence by said timing device.

18; In an acetylene 1' generating plantas claimed in claim 17 and having means for feeding carbide and water to a generating chamber and means for agitating the mixture of materials within the generating chamber, and in which said interlocking circuits include automatic starter switch relays for controlling the operation of the mixture agitating means and for controlling the operation of the carbideteeding means, said interlocking circuits also including means for de-energizing the relay for the carbide-feeding means if the circuit of the 1 relay for the mixture-agitating means becomes interrupted. I

19.111 an acetylene generating plant as claimed in claim 1'7 and having a motor-driven conveyer. and a solenoid-operated water valve- 1 respectively provided for feeding carbide and water to. a generating chamber, "and in which said interlocking circuits include an automatic starter switch relay for the conveyor motor, and the circuit-of the solenoid of said water valve being interlocked with the circuit of the relay for said conveyormotor whereby the ,interrup-- tion of said conveyor motor circuit efiects closing of the .water valve. 20. In an acetylene generating plant as claimed in claim 1'7 and having a motor-driven conveyor and a solenoid-operated .water .valve 20 respectively provided for feeding carbide and water to a generating chamber, and in which said interlocking circuits include an automatic starter switch relay for the conveyor motor and t a second relayadapted' to be energized in the event that the relay for said conveyor motor becomes de-energized,'s aid second relay being interlocked with the solenoid of said water valve,

whereby said solenoid is de-energized upon energization of said second. relay.

21. In an acetylene generating plant as claimed in claim 17 and having means for feeding carbide andwater to a generating chambe and inwhi ch the automatic starter switch relay for the residue-conveying device is interlocked with-an interrupter relay in such manner that said interrupter relay becomes energized upon de-energizati'on ofthe starter switch relay for the residue-conveying device to therebyinter mm the circuits controlling the water-feeding 40 means and the carbide-feeding means.

WILLIAM G. CHESTER A. 

